Method of producing tobacco-containing foils



March 20, 1962 7 RV GROSSTEINBECK ETAL 3,025,860

METHOD OF PRODUCING TOBACCO-CONTAINING FOILS Filed June 2, 1960 FIG.

Fl LJLJ BY H M @WLA W 6 INVENTORS fig sates The present invention relates to a method of producing tobacco-containing foils, and more particularly, the present invention relates to a method of producing foils having great mechanical strength and containing a large percentage of tobacco.

In recent years, considerable attention has been paid the problem of utilizing tobacco waste accruing in the tobacco processing industry, particularly in the manufacture of cigars and cigarettes.

Various attempts have been made to utilize the portions of the tobacco leaf which initially could not be initially could not be incorporated ito the finished tobacco product. Such portions include the ribs of the tobacco leaf, tobacco dust and the like. It has been attempted to reform such tobacco waste into foils which then could be processed more or less in the same manner as the original tobacco leaves. For instance, methods have been worked out which are comparable to methods used in the paper industry. However, the wet strength of tobacco foils formed in this manner was unsatisfactory. It has been attempted to overcome this ditliculty by incorporating cellulose having a relatively great fiber length into the mixture. However, these attempts have met with only a very limited success and did not result in a fully satisfactory product. It has then been attempted to apply a mass of wet pulverulent tobacco onto a finished or semifinished paper web and to form in this manner tobaccocontaining foils consisting of a carrier layer and a tobacco layer. However, foils produced in this manner necessarily contain relatively large proportions of non-tobacco constituents and, furthermore, these foils do not possess a coherence sutficient, for instance, for the use thereof as cigar wrappers.

It has then been attempted to form mixtures with an adhesive binder and pulverulent tobacco and to roll or calender such mixtures to tobacco-containing foils. Again, a relatively large proportion of binder material is required and thereby the quality of the finished product is necessarily lowered. The same disadvantages are inherent in other methods such as spraying of alternate layers of adhesive binder and tobacco dust onto a temporary carrier or support and subsequently removing from the support a foil formed of these sprayed binders and tobacco layers.

In addition to the above discussed disadvantages, all of these methods require a rather considerable investment in machinery and lab or, particularly if it is attempted to produce foils of continuously even qualities and tobacco content.

It is therefore an object of the present invention to overcome the above discussed distadvantages and difficulties of prior art methods concerned with the utilization of tobacco waste and the like.

It is a further object of the present invention to provide a method for forming in a simple and economical manner homogeneous foils of high tobacco content.

It is yet another object of the present invention to provide a method for transforming pulverulent tobacco or tobacco waste into a foil product which may contain up to about 90% tobacco and which will be excellently suitable as a wrapper leaf for cigars as well as for producing ice therefrom other products which can be made of tobacco leaves.

Other objects and advantages of the present invention will become apparent from a further reading of the de scription and the appended claims.

With the above and other objects in view, the present invention contemplates a method of producing tobaccocontaining foils, comprising the steps of intimately mixing finely subdivided tobacco and a liquid binder adapted to be solidified by contact with a precipitating bath so as to form a flowable suspension consisting essentially of the finely subdivided tobacco and of the liquid binder, and extruding a thin layer of the fiowable suspension into a precipitating bath adapted to solidify the liquid binder so as to solidify the same and to transform the extruded suspension into a tobacco-containing foil.

Thus, according to the present invention, it is possible in an effective and simple manner to utilize tobacco waste (or any other tobacco product which either accrues in pulverulent condition or may be comminuted to the desired fineness). The apparatus required for producing the foils of the present invention consists essentially of devices which are conventional in the production of synthetic foils. As binder, substantially any material can be used which is capable of being spun or of being extruded into foils with the use of a precipitating bath. It is, of course, desirable to select such binder materials which will not possess any harmful or otherwise undesirable qualities, particularly, binders will be preferred which do not impart a taste during the smoking of the finished product and which burn or glow evenly together with the tobacco, or will be transformed into a constituent of the tobacco ash conforming to the general structure and texture of the latter.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIGS. 1 and 2 illustrate devices for carrying out the method of the present invention.

Referring now to the drawing, the flowable suspension consisting of finely subdivided tobacco distributed in a hardenable liquid binder is extruded through elongated slit nozzle 1 into precipitating bath 2. Thereby, the sus pension is transformed into a foil which passes via conveying rolls 4 and heating rolls 5 to drier 6. For this purpose, i.e. the conveying of the freshly formed foil, it is also possible to use the endless textile belt 7 illustrated in FIG. 2. The dried foil is then wound onto storage reel 8.

According to the present invention, the binder is dissolved in a suitable solvent such as water, methylene chloride, acetone or one of the lower alcohols, and the finely ground tobacco or tobacco waste is then mixed with the binder solution so as to form an extrudable, flowable suspension which is then extruded through a conventional elongated slit nozzle into a precipitating bath, in a manner substantially similar to the extrusion of synthetic foil material. It is, thus possible to produce a tobacco-containing foil of substantially unvarying thickness.

As binders or binding agents, primarily cellulose derivativessuch as methyl cellulose, acetyl cellulose carboxymethyl cellulose and cellulose ethyl ether are found to be particularly suitable. However, it is also possible to produce the tobacco containing foils with other binders, for instance, binders consisting of galactans, manans, gum arabic, tragacanth, dextrin and gelatin.

It is also within the scope of the present invention to include in the suspension tobacco additives such as filler materials and combustion catalysts or retardants, or other additives which will be suitably chosen taking into consideration the specific binder which will be used for forming the tobacco-containing foil.

As will be further shown in the examples, a relatively large quantity of finely ground tobacco and tobacco waste is suspended in the binder solution. The suspension is then extruded into the precipitating bath through an elongated slit nozzle, the dimensions of which are chosen or adjusted so as to obtain a foil of desired width and thickness.

In the case of organic binder solvents, preferably water is used as the precipitating agent, while for aqueous binder solutions, water miscible precipitants such as sulfuric acid, glycerol, glycol or sorbitol are used advantageously.

The thus extruded continuous foil is then dried and wound up onto a storage reel.

Thus, according to the present invention, tobaccocontaining foils consisting predominantly of pulverulent tobacco waste can be produced which on the one hand possess the desired mechanical strength characteristics and on the other hand include a very high proportion of tobacco.

The following examples of tobacco-containing suspensions which may be extruded into foils in accordance with the present invention are given as illustrative only without, however, limiting the invention to the specific details of the examples:

Example I 50 parts by weight of acetyl cellulose 212 parts by weight of tobacco powder 52 parts by weight of glycerol 4 parts by weight of potassium nitrate 250 parts by weight of methanol 500 parts by weight of ethyl acetate Example II 62 parts by weight of acetyl cellulose 200 parts by weight of tobacco powder 5 2 parts by weight of glycerol 4 parts by weight of magnesium carbonate 52 parts by weight of methanol 5 00 parts by weight of ethyl acetate Example 111 35 parts by weight of acetyl cellulose 227 parts by weight of tobacco powder 52 parts by weight of ethylene diglycol 4 parts by weight of magnesium carbonate 250 parts by weight of methanol 500 parts by weight of ethyl acetate Example IV 28 parts by weight of carboxymethyl cellulose 100 parts by weight of tobacco pawder 20 parts by Weight of glycerol 4 parts by Weight of potassium nitrate 667 parts by weight of water Example V parts by weight of carboxymethyl cellulose 113 parts by weight of tobacco powder parts by weight of ethylene diglycol 4 parts by weight of magnesium carbonate 667 parts by weight of water The compositions of Examples I-III are suitable for precipitating a water-insoluble foil by extruding the composition through the slit nozzle into the water bath. Solidification of the foil Will occur instantaneously due to precipitation of the acetyl cellulose, and the thus formed foil may then be passed on an endless carrier t through a drying chamber and thereafter wound up in dry condition as, for instance, illustrated in FIG. 2 of the drawing.

The compositions of Examples IV and V are used for precipitation of the foil in precipitating agents such as aqueous solutions of sulfuric acid, glycerol, glycol or sorbitol. Again, the material is extruded through the slit nozzle into the precipitating bath. The thus formed foil may then be squeezed between rollers and subsequently dried as, for instance, illustrated in FIG. 1 of the drawing.

In the examples, the proportion of tobacco in the finished foil will be between 75 and 88%, while the binder will amount to between 11 and 23% of the weight of the finished foil.

Tear resistance of the tobacco containing foil is improved with an increase in the proportion of binder. However, on the other hand, it is desired to have a maximum proportion of tobacco in order to produce a foil the taste of which diflers as little 'as possible from the taste (odor and aroma) of tobacco.

The method of the present invention permitsdue to instantaneous precipitation and felting of the tobacco binder mixture-to produce foils which contain up to about 90% tobacco and still will possess the desired tear strength.

The binder and the precipitation bath suitable for the chosen binder are selected in accordance with the specific requirements as well as economic considerations primarily however by taking into consideration the taste, aroma and odor desired in the finished product particularly during combustion of the same.

Thus, compositions according to Examples IV and V will have less influence on the tobacco qualities than the compositions of Examples I to III. However, the expenses involved in connection with the precipitating bath according to Examples IV and V are higher than those in Examples I to III.

Preferably, tobacco or tobacco Waste is ground so finely that the pulverulent product will pass through a very fine sieve without leaving a considerable residue. The more finely the tobacco is ground, the more homogeneous will be the surface of the tobacco-containing foil.

Certain tobacco additives are mentioned in the examples, such as potassium nitrate and magnesium carbonate as combustion improving agents, or glycerol and ethylene diglycol as humectants. Ethylene diglycol endows the product with a longer shelf life. However, it is more expensive than glycerol which in combination with tobacco generally possesses a more limited shelf life.

The addition of these tobacco additives does not appreciably influence the tearing strength of the foil but only the quantitative relationship between tobacco and nontobacco constituents of the product.

In carrying through the Examples I-Ill the used tobacco waste is dryly ground, sieved, e.g. through a very fine sieve and the sieved material is mixed with the corresponding binder dissolved in the named solvents (methanol and ethyl acetate).

Then the plasticizer (glycerol or ethylene diglycol and the combustion improving agent (potassium nitrate or magnesium carbonate) are added and the resulting mixture is stirred until homogenization takes place. The above mentioned steps are carried through at ambient temperatures.

The homogeneous suspension is then pumped to the slit nozzle which is contained in the water bath which acts as precipitating bath and which is held on a temperature of about 20 C.40 C. The precipitated foil is then passed on an endless carrier through a drying chamber of a temperature of about C.-180 C., preferably about C. C. Thereafter the dried foil is slightly wetted with water by spray nozzles to a water content of 15-25 percent by weight, preferably about 20 percent by weight and wound up on a bobbin.

In carrying through the Examples IV and V the proccdure is the same as in Examples I-III with the exception that an aqueous solution of the binder is used and the homogeneous suspension is precipitated e.g. in diluted sulfuric acid (concentration of l5%) or glycerol or glycol. If sulfuric acid (or another acid) is used as precipitating bath it is necessary to include a washing step of the precipitated foil before drying. The following drying and wetting steps are the same as above described for the Examples I-IH.

The slit nozzles are formed in such a way that the prepared tobacco foils have a thickness of about 0.050.3 mm. Foils of a thickness of about 0.10-0.15 mm. are preferred.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco and a liquid binder adapted to be solidified by contact with a precipitating bath so as to form a flowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said fiowable suspension into a precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

2. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco, tobacco additives and a liquid binder adapted to be solidified by contact With a precipitating bath so as to form a flowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said fiowable suspension into a precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

3. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco and a liquid binder adapted to be solidified by contact with Water so as to form a flowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said fiowable suspension into a water bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobaccocontaining foil.

4. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco and a solution of acetyl cellulose as a liquid binder adapted to be solidified by contact with Water so as to form a ilowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said flowable suspension into a water bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

5. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco and a liquid binder adapted to be solidified by contact with a precipitating bath consisting essentially of a mixture of water and a water miscible precipitating agent so as to form a ilowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said flowable suspension into said precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

6. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco and a liquid binder adapted to be solidified by contact with a precipitating bath consisting essentially of a mixture of water and a water miscible precipitating agent selected from the group consisting of sulfuric acid, glycerol, glycol and sorbitol so as to form a ilowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said fiowable suspension into said precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

7. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco and a solution of carboxymethyl cellulose as a liquid binder adapted to be solidified by contact with a precipitating bath consisting essentially of a mixture of water and a Water miscible precipitating agent selected from the group consisting of sulfuric acid, glycerol, glycol and sorbitol so as to form a flowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said fiowable suspension into said precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

8. A method of producing tobacco-containing foils, comprising the steps of intimately mixing finely subdivided tobacco substantially capable of passing through a very fine sieve and a liquid binder adapted to be solidified by contact with a precipitating bath so as to form a fiowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said fiowable suspension into a precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

9. A method of producing tobacco-containing foils, comprising the steps of intimately mixing between about and parts by weight of finely subdivided tobacco and between 10 and 25 parts by weight of a liquid binder adapted to be solidified by contact with a precipitating bath so as to form a fiowable suspension consisting essentially of said finely subdivided tobacco and of said liquid binder; and extruding a thin layer of said flowable suspension into a precipitating bath adapted to solidify said liquid binder so as to solidify the same and to transform said extruded suspension into a tobacco-containing foil.

References Cited in the file of this patent UNITED STATES PATENTS 1,740,226 Czapek et al. Dec. 17, 1929 1,892,657 Von Hoessle Dec. 27, 1932 2,613,673 Sartoretto et a1 Oct. 14, 1952 FOREIGN PATENTS 282,369 Great Britain printed 1929 

1. A METHOD OF PRODUCING TOBACCO-CONTAINING FOILS, COMPRISING THE STEPS OF INTIMATELY MIXING FINELY SUBDIVIDED TOBACCO AND A LIQUID BINDER ADAPTED TO BE SOLIDIFIED BY CONTACT WITH A PRECIPITATING BATH SO AS TO FORM A FLOWABLE SUSPENSION CONSISTING ESSENTIALLY OF SAID FINELY SUBDIVIDED TOBACCO AND OF SAID LIQUID BINDER; AND EXTRUDING A THIN LAYER OF SAID FLOWABLE SUSPENSION INTO A PRECIPITATING BATH ADAPTED TO SOLIDIFY SAID LIQUID BINDER SO AS TO SOLIDIFY THE SAME AND TO TRANSFORM SAID EXTRUDED SUSPENSION INTO A TOBACCO-CONTAINING FOIL. 